Semiconductor component and method for producing the same

ABSTRACT

A method for producing a semiconductor component with adjacent Schottky ( 5 ) and pn ( 9 ) junctions positions in a drift area ( 2, 10 ) of a semiconductor material. According to the method, a silicon carbide substrate doped with a first doping material of at least 10 18  cm −3  is provided, and a silicon carbide layer with a second doping material of the same charge carrier type in the range of 10 14  and 10 17  cm −3  is homo-epitaxially deposited on the substrate. A third doping material with a complimentary charge carrier is inserted, and structured with the aid of a diffusion and/or ion implantation, on the silicon carbide layer surface that is arranged far from the substrate to form pn junctions. Subsequently the component is subjected to a first temperature treatment between 1400° C. and 1700° C. Following this temperature treatment, a first metal coating is deposited on the implanted surface in order to form a Schottky contact and then a second metal coating is deposited in order to form an ohmic contact. Subsequently the first and second metal coatings are structured as designed.

[0001] The invention relates to a semiconductor component withalternating Schottky and pn junctions and low-doped drift zones of asemiconductor material, which are arranged between the Schottky and pnjunctions, as well as a method for producing a component.

[0002] In addition to pn diodes, Schottky diodes are also used ascomponents for low operating voltages. Schottky diodes are distinguishedthrough low on-state voltages and low switching losses. In order toreduce the field peaks occurring at the edge of the Schottky junction,so-called guard rings are frequently provided at the edge of thecomponent. These guard rings reduce the field peaks occurring at theedge of the Schottky junction and advantageously contribute to theincrease in the breakdown voltage of the component.

[0003] However, the series resistances in the component as well as theoff-state leakage currents increase with an increase in the breakdownvoltage of the diode, particularly with increased temperatures. Abroader use of the Schottky diodes, which are in reality very simpletechnologically, is thus made more difficult.

[0004] The strong dependence of the off-state leakage current on thevoltage, owing to the voltage-induced deformation of the energeticbarrier of the Schottky junction, presents a particular problem. TheSchottky barrier is reduced at the barrier by an applied off-stagevoltage and therewith connected electrical field, so that the off-stateleakage current increases strongly with the off-state voltage and canhave very high values, even prior to the actual breakdown. In addition,the off-state currents show an exponential increase along with thetemperature, owing to the underlying thermal emission mechanism, whichresults in an unfavorable rejection characteristic.

[0005] Schottky diodes made from different semiconductor materials areknown. In the EP 380 340 A2, a Schottky diode made of SiC is described.In the article by L. Wang et al., “High Barrier Height GaN Schottkydiodes: Pt/GaN and Pd/GaN” in Appl. Phys. Lett. 68(9),Feb. 26, 19961267-1269, Schottky diodes made of GaN are disclosed. The German Patent42 10 402 A1 discloses Schottky diodes made of diamond lattice.

[0006] In literature, various approaches are described for improving therejection characteristic, e.g. in B. M. Wilamowski, “Schottky Diodeswith High Breakdown Voltages,” Solid-State Electronics, vol. 26(5), p.491-493, 1983, and in B. J. Baliga, “The Pinch Rectifier: ALow-Forward-Drop High-Speed Power Diode,” IEEE Electron Device Letters,EDL-5(6), 1984. It is assumed therein that a screening reduces theelectrical field intensity at the Schottky junction. The componentdescribed therein is a so-called “Merged-pn/Schottky (MPS) Rectifier,”which has inside the guard ring arrangement alternating Schottkycontacts and highly doped pn junctions with n-drift zones of asemiconductor material arranged in-between. To be sure, the rejectioncharacteristic of these components is improved, but there are severaldisadvantages.

[0007] In addition to the loss of active surface for the Schottkyjunctions, in particular the injection of minority charge carriers fromthe highly doped semiconductor area is a disadvantage during the forwardoperation of the pn contacts. With a forward polarity of the MPScomponent, the current initially flows only over the Schottky regions.With further increasing forward voltage, the pn junctions also enter thepassage range, wherein minority charge carriers are injected into thedrift zone. In contrast to the components having only guard ringarrangements, this minority charge carrier injection cannot be neglectedsince the charge carrier injection can even result in the formation ofelectron-hole plasma, in the same way as for pure pn diodes. On the onehand, the passage properties are slightly improved while, on the otherhand, the switching losses increase sharply.

[0008] Literature describes a series of measures for improving theswitching behavior and rejection characteristic of the MPS components.The U.S. Pat. No. 5,262,669 A discloses arranging the pn junctions forMPS components in etched grooves, as well as adapting the geometry ofthe pn junctions to the barrier height of the Schottky junction or thespace charge zone that forms at the Schottky junction. The technologiesand arrangements used, however, are technologically very involved. Forthat reason, the MPS components are practically unimportant, despitetheir generally simple production technology and advantageouscharacteristics of unipolar diodes.

[0009] It is the object of the invention to specify a MPS component, forwhich the switching losses are improved without the use of involvedtechnological steps.

[0010] This object is solved by the features in the independent claims.Modified and advantageous embodiments follow from the dependent claimsand the description.

[0011] The invention concerns an arrangement with a junction betweenSchottky metal and drift zone of a semiconductor, as well as a screeningof pn junctions, which screening is essentially embedded in the abovejunction. A minimum difference between energetic height of the Schottkybarrier and the energy gap of the semiconductor material must bemaintained here for the selection of materials for semiconductor andSchottky metal.

[0012] It is advantageous if the simple technology of the MPS componentscan be used and the rejection characteristics as well as the shutdownlosses are improved.

[0013] It is particularly advantageous if semiconductors withhigh-energy gap, particularly so-called ‘wide-band gap’ semiconductors,are used. It is favorable if the material for the Schottky contact isselected such that it does not fall below a minimum barrier height. Therejection characteristics are thus improved.

[0014] In one preferred embodiment, the drift zone consists of siliconcarbide, while in another embodiment, the drift zone consists of galliumnitride. In a further embodiment, the drift zone consists of aluminumnitride while that of another one consists of diamond lattice.

[0015] In one preferred embodiment, a drift zone with identical type ofconductivity but lower doping is arranged on a highly doped substratematerial of silicon carbide. It is advantageous if a substrate materialdoping of higher or equal to 10¹⁸ cm⁻³ and a drift zone doping of 10¹⁴to 10¹⁷ cm⁻³ is used.

[0016] One advantageous embodiment has a drift zone with a thickness ofbetween 2 μm and 50 μm.

[0017] The distance between adjacent pn junctions for one preferredembodiment is between 0.5 μm and 20 μm.

[0018] In another preferred embodiment, the pn junctions are arranged ingrooves that are etched into the inner drift zone.

[0019] The Schottky junctions of one preferred embodiment are arrangedadjacent to the pn junctions in the drift zone.

[0020] The highly doped regions in the drift zone of one preferredembodiment are formed by the drift zone semiconductor material withcomplementary doping.

[0021] In another preferred embodiment, the highly doped regions in thedrift zone are formed by different semiconductor materials.

[0022] One favorable embodiment has aluminum and/or boron inserted intothe doping region for the p-doped substrate material.

[0023] Nitrogen and/or phosphor are inserted in one favorable embodimentfor the n-doped substrate material.

[0024] The cathode and anode of another preferred embodiment arearranged on opposite surfaces of the semiconductor component.

[0025] One preferred embodiment provides that the cathode and anode arearranged on the same semiconductor component surface. In particular, oneouter contact encloses the other outer contact.

[0026] An essentially pointed contacting occurs between an outer contactand the drift zone of one preferred embodiment.

[0027] In another preferred embodiment, a highly doped semiconductorregion is positioned in front of the cathode, which region has the sametype of conductivity as the drift zone of the semiconductor.

[0028] It is particularly favorable that a component according to theinvention can also be designed as complementary doped component.

[0029] A method according to the invention specifies the production of asilicon carbide component according to the invention. In one preferredembodiment, a particularly favorable temperature treatment is carriedout. The advantage is that the surface roughness of the component is notmade worse during the temperature treatment.

[0030] The features, insofar as they are essential to the invention, areexplained in detail in the following and with the aid of the Figures,wherein:

[0031]FIG. 1 Shows the course of characteristic curves for componentsaccording to the invention and that of curves for various knowncomponents;

[0032]FIG. 2 Shows a section through a Schottky diode with guard ring,according to prior art;

[0033]FIG. 3 Shows a section through a MPS component according to priorart;

[0034]FIG. 4 Shows the characteristic shutdown curve for a componentaccording to the invention, as compared to the curve for a pn diodeaccording to prior art;

[0035]FIG. 5 Shows a section through a MPS component according to theinvention;

[0036]FIG. 6 Shows a section through a MPS component according to theinvention.

[0037]FIG. 2 shows a section through a Schottky diode with guard ring,according to prior art. In the standard arrangement, a low-doped n⁻semiconductor region 2, particularly an epitaxial layer, is arranged ona highly doped n substrate 1. A Schottky contact is arranged on thesurface of the semiconductor layer 2, which is formed with a first metallayer, the Schottky metal 3, and a second contacting metal system 4. TheSchottky junction 5 forms toward the semiconductor. The Schottky contactforms the anode A. On the side of substrate 1 that is opposite the anodeA, a third contacting metal system 6 is arranged, which forms thecathode K. A highly doped semiconductor region 7 with a charge carriertype that complements that of the semiconductor region 2 is arrangedbelow the edge region of the Schottky contact arrangement. Thesemiconductor region 2 represents the drift zone for the charge carrier.The semiconductor region 7 forms the protective ring (the so-called“guard ring”), which reduces the electrical field peaks that otherwiseoccur at the edge of the Schottky contact and thus increase itsbreakdown voltage.

[0038]FIG. 3 furthermore shows a modified version of the arrangementaccording to FIG. 2, in the form of a section through a standard MPScomponent according to prior art. In this arrangement, the field peaksare further reduced through a screening below the Schottky contact. Thescreening consists of a grid of highly doped semiconductor regions 8,which contain a charge carrier type that is complementary to thesemiconductor layer 2, the same as the guard ring 7. The screeningarrangement 7 in FIG. 3 is formed by p-regions. Essentially, anarrangement is formed with alternately arranged Schottky junctions 5 andpn junctions 9, as well as drift zones 10 in-between.

[0039] If an off-state voltage is applied to this arrangement betweenanode A and cathode K, then the space charge zone expands withincreasing voltage not only from the Schottky junction, but also fromthe semiconductor regions of the screening arrangement 8. With standarddimensioning, the Schottky regions are cut off between the p-regions 8from their space charging zones, so that the electrical field intensityat the Schottky junction 5 barely increases further. This arrangementcorresponds approximately to a cascode of a Schottky diode and aso-called ‘static induction transistor.’

[0040] This structure per se already shows the advantageous reduction ofthe strong dependence of the off-state current on the voltage andresults already an improved rejection capacity of the MPS component. Atthe same time, the technological conversion of the structure is verysimple. In particular, it is possible with standard diodes to create ascreening arrangement 8 in the form of a lattice or other suitablegeometry, particularly strips and points, in one technological step andtogether with the guard ring 7, if necessary also with several so-calledfield rings. There is no additional technological expenditure.

[0041] One disadvantage of the known structure is that active Schottkysurface is lost. A great disadvantage is that during the forwardoperation of the component, minority charge carriers are injected fromthe screening regions 7 into the drift zone of the semiconductor region2. With a forward polarity of the MPS component, the current initiallyflows only over the Schottky regions. With further increasing forwardvoltage, however, the pn junctions 9 are also subject to passage,wherein minority charge carriers are injected into the drift zones 2 and10. As a result of the relatively large surface share of the screeningarrangement 8, particularly the p+ regions, this injection can no longerbe neglected, as is the case with the Schottky diodes with guard ring 7.

[0042] This occurrence can lead to the forming of an electron holeplasma in the drift zone of the semiconductor region 2, which improvesthe passage characteristics, to be sure, but causes considerableswitching losses in the component.

[0043] According to the invention, a material combination is selectedfor the semiconductor material and the Schottky material, which ensuresthat the difference of the size of the energetic band gap in theelectronic excitation spectrum of the semiconductor and the energeticheight of the Schottky barrier in the non-voltage state of the componentis higher or equal to a predetermined energy value, preferably at least0.8 eV, and even more preferably at least 1 eV. Simplified, it can beassumed that for a pn junction a voltage is necessary that is higher bythe difference value ΔU than is necessary for the Schottky contact inorder to allow the same current I_(o) to flow. The difference value ΔUfor a MPS component according to the invention can simply be interpretedto be the voltage difference between a total current I_(o), startingwith a first voltage and the injection current with the same level asI_(o), which starts with a second, higher voltage.

[0044] The relationship between the energy values and the voltagedifference ΔU results in ΔU=(E_(gap)−φ_(barrier))/q_(o)+k, whereinE_(gap) is the energy gap of the semiconductor, φ_(barrier) is theheight of the Schottky barrier, q_(o) the elementary charging constantand k the constant that depends on the effective Richardson constant,the temperature, the charge carrier state densities, the charge carriermobility, the charge carrier life expectancy, the doping and the surfaceratio between Schottky junction and pn junction surface. For standardparameter values of comparable components, k is in the range of several10 mV to a few 100 mV and thus can essentially be neglected. TheSchottky barrier φ_(barrier) is preferably determined from the forwardcharacteristic of the diode in the manner known per se.

[0045] The absolute values for the band gap E_(gap) and the Schottkybarrier φ_(barrier) are not important for the voltage difference ΔU.Owing to the fact that the higher the voltage difference ΔU, the lowerthe switching losses, it makes sense to select suitable semiconductorSchottky material combinations.

[0046] Materials with a high band gap E_(gap) should preferably beselected for the semiconductor materials. Particularly suitable arevarious poly types of silicon carbide, gallium nitride, aluminum nitrideand diamond. When selecting the optimum Schottky contact material, itmust be observed that on the one hand, the Schottky barrier φ_(barrier)is small enough to achieve the highest possible energy differencebetween band gap E_(gap) and Schottky barrier φ_(barrier) height while,on the other hand, the Schottky barrier is high enough to achievefavorable rejection characteristics. It is particularly favorable if theSchottky barrier φ_(barrier) height is selected higher than 0.5 eV, andin particular higher than 0.8 eV. It makes sense to have a Schottkybarrier φ_(barrier) height of less than 2 eV. Thus, the componentaccording to the invention is particularly well suited for use in thehigh off-state voltage range, preferably for a range higher than 200 Vand especially higher than 600 V.

[0047] Particularly advantageous as semiconductors are combinations ofsilicon carbide with metals, especially titanium, aluminum, palladium,gold, silver, nickel or metal combinations, particularlytitanium/aluminum, titanium/nickel/silver or the like with silicides. Inparticular, these include TiSi₂ or other suitable metal/semiconductorcombinations, which meet the requirement that the difference betweenband gap E_(gap) and barrier Schottky φ_(barrier) height must be higheror equal to 0.8 eV, preferably 1 eV.

[0048] If a MPS component with the material combination according to theinvention is operated in forward direction, then the pn junctions 9 donot inject minority charge carriers into the drift zone of thesemiconductor until clearly higher flux voltages exist. This is shown inFIG. 1. In that case, only a negligible injection occurs during thenormal diode operation, so that no additional switching losses occur asa result of the so-called ‘clearing out’ of minority charge carriersfrom the drift zone, or owing to a possible return-flow peak. This isshown in FIG. 4.

[0049] In FIG. 1, a comparison is made in forward as well as off-statedirection between measured characteristic curves for silicon carbide MPScomponents according to the invention, having different screeninggeometries M, and the characteristic curves of other components,particularly Schottky diodes S, Schottky diodes with guard ring G aswell as pn diodes PN. The advantageous effect of the arrangementaccording to the invention is shown clearly. With the MPS components Maccording to the invention, a high current in forward direction flows atvery low voltages already, similarly as for the components S and G thatare favorable in forward direction. By comparison, clearly highervoltages must be applied to the pn diode PN for comparable flows. In theoff-state direction, the leakage current for the MPS components Maccording to the invention is clearly lower than for the Schottky diodesS and G, with and without guard ring, and shows similarly favorablerejection characteristics as for the pn diode PN.

[0050]FIG. 4 shows the characteristic curves of a component according tothe invention, made of SiC and those of a comparable component made ofSi, which characterize the shut-down behavior of the components. Thecomponents are shut down by 1A forward current against 500 V off-statevoltage. The Si component is a pn diode and demonstrates thecharacteristically poor shutdown behavior. The characteristic curve forthe Si component drops sharply and shows a strong reverse recovery tohigh negative flows, which are considerably higher than the actualforward current of 1A. This can be traced back to the fact that numerousminority charge carriers must be removed from the drift zone of thesemiconductor, which results in extremely disadvantageous switchingbehavior with high switching losses for the this Si component.

[0051] In contrast, only a few minority charge carriers exist in thedrift zone for the component according to the invention, since theinjection of these carriers is for the most part prevented by thevoltage difference ΔU according to the invention. The current in thereverse recovery range therefore amounts to only a fraction of theactual forward current. The shutdown of the component according to theinvention therefore occurs as quickly as that of pure Schottky diodes,for example, which are known for their rapid shutdown characteristics.However, the off-state losses are clearly improved. The switching lossesas compared to the pn diodes are reduced considerably. Thus, thecomponent according to the invention on the one had exhibits thefavorable characteristics of the known Schottky diodes, e.g. reducedswitching losses and simple technology, but also shows clearly loweroff-state leakage currents.

[0052] The advantage of having lower switching losses with higheroff-state stability, however, is also met for those components accordingto the invention, for which the off-state current behavior is notfurther improved owing to the particularly high energy gap of thesemiconductor, provided the difference value between energy gap andSchottky barrier height is at least 0.8 eV, preferably at least 1 eV.

[0053] To be sure, the preferred embodiments of the MPS componentsaccording to the invention, illustrated in the Figures, show verticalcomponents with the external connections for cathode K and anode Aarranged on opposite surfaces of the semiconductor. However, a componentaccording to the invention can also be designed as a lateral componentwhere the external contacts for anode A and cathode K are arranged onthe same surface of the semiconductor. In particular, the one externalcontact can enclose the other one, e.g. the cathode can surround theanode in the shape of a ring. In one preferred embodiment, an externalcontact, in particular the cathode K, contacts the semiconductor driftzone only in points.

[0054] In another preferred embodiment, a highly doped semiconductorregion with the same conductivity type as the drift zone for thesemiconductor 2 is arranged in front of the cathode. Advantageously,this results in an improved contact between semiconductor and cathodecontact, and a possible expansion of the space charging zone toward thecathode metal 6 (so-called ‘punch through’) is thus cut off.

[0055] The invention also applies to MPS components with complementarydoping.

[0056] In one preferred embodiment, highly doped n-conducting orp-conducting silicon carbide, preferably n-conducting 4H siliconcarbide, is used as substrate 1, particularly one having more than 10¹⁸cm⁻³. The arrangement is similar to the one described in FIG. 3. A driftzone 2 with identical charge type as the substrate 1 is arranged on thissubstrate, preferably through homo-epitaxial precipitation. Thethickness of the drift zone is preferably between 2 μm and 50 μm. Thedoping is preferably between approximately 10¹⁴ and 10¹⁷ cm⁻³.

[0057] Doping material atoms are inserted structured into the drift zone2, essentially in areas near the surface. Drift zone 10 and dopingregions 7, 8 alternate. Aluminum or boron are preferably selected for ap-type drift zone and nitrogen or phosphor are selected for an n-typedrift zone. The resulting regions 7 and 8 are of the opposite chargecarrier type than the charge carrier type of drift zone 10 and form pnjunctions 9.

[0058] The structured doping materials can be inserted into the surfaceof drift zone 2 by means of diffusion or, preferably, by means of ionimplantation techniques. The spacing between doping regions 7 and 8 canbe optimized, such that possibly existing non-operative space chargingzones of neighboring pn junctions 9 do not touch. As a result, thecharge carrier passage in forward direction is not obstructed. On theother hand, the pn junctions 9 must be positioned close enough, so thatif an off-state voltage is present at the component, the region betweenneighboring pn junctions 9 is securely cut off by the space chargingzones in region 10, which expand with the increasing off-state voltage.

[0059] In addition to the doping and the semiconductor material, theoptimum distance between the pn junctions 9 also depends on the geometryof the pn screening 8, which in particular can have a strip, lattice,ring, spiral, hexagonal or point structure.

[0060] It is preferable if the distance between neighboring pn junctionsis between 0.5 μm and 20 μm.

[0061] A temperature treatment preferably follows the insertion of thescreening, especially one between 1400° C. and 1700° C., which healspossible implantation damage, drives the doping material deeper andthermally activates the material. Particularly advantageous is amulti-stage temperature treatment, as disclosed in the German PatentApplications DE 196 33 183 and DE 196 33 184. These applicationsdisclose the temperature treatment of semiconductor components withvolatile, particularly sublimating components, especially siliconcarbide. The method consists of carrying out the temperature treatmentin such a way that the component is kept for a limited interval first ata temperature of between 500° C. and 1500° C. and subsequently at atemperature of more than 1500° C. It is particularly advantageous ifduring the temperature treatment silicon is added directly adjacent tothe component, particularly in a possibly existing healing pan in whichthe component is stored during the temperature treatment. This has theparticular advantage that the surface of the MPS component remainssmooth during the actual healing step, owing to a preceding conditioningstep, despite the high temperature. Subsequently, the meallization forthe front (Schottky metal) and rear (ohmic contact) is deposited, isstructured and, if necessary, thermally treated.

[0062]FIG. 5 shows a component according to the invention, into whichgrooves are etched in the drift zone 2 prior to inserting the doping forthe screening and at the locations intended for the screening. This hasthe advantage that the pn junctions extend far into the drift zone 2,thereby improving the cut-off of the Schottky regions.

[0063] In another preferred arrangement that is shown in FIG. 6, anepitaxial layer is deposited after the screening zones 8 are installed,which epitaxial layer has the same conductivity as the drift zone 2.Consequently, the screening zones 8 are buried. The screening zones aresubsequently freed again, particularly etched free and are metallizedonly after that. In this way, the active Schottky surface is expanded bythe side surfaces of the etched areas, which at least compensates, inparticular over-compensates, for the surface loss due to the screeningzones 8.

1. A semiconductor component with outer contacts as anode and cathodeand with a guard ring (7), comprising alternately arranged Schottkyjunctions (5) and pn junctions (9) that are arranged near the surface,as well as low-doped drift zones (10) of a semiconductor material (2)that are arranged between the Schottky junctions and the pn junctions,characterized in that the energy difference (E_(gap)−φ_(barrier))between the band gap (E_(gap)) in the electronic excitation range of thedrift zone semiconductor (2) and the energetic height (φ_(barrier)) ofthe Schottky barrier (5) is at least 0.8 eV in the non-voltage state ofthe semiconductor component and the band gap (E_(gap)) is higher than1.5 eV.
 2. A semiconductor component according to claim 1, characterizedin that the energy difference (E_(gap)−φ_(barrier)) is at least 2 eV. 3.A semiconductor component according to at least one of the precedingclaims, characterized in that the energetic height of the Schottkybarrier (φ_(barrier)) is less than 2 eV.
 4. A semiconductor componentaccording to at least one of the preceding claims, characterized in thatthe energetic height of the Schottky barrier (φ_(barrier)) is higherthan 0.5 eV.
 5. A semiconductor component according to at least one ofthe preceding claims, characterized in that the semiconductor materialof the drift zones (2, 10) is silicon carbide.
 6. A semiconductorcomponent according to at least one of the preceding claims,characterized in that the semiconductor material of the drift zones (2,10) is gallium nitride.
 7. A semiconductor component according to atleast one of the preceding claims, characterized in that thesemiconductor material of the drift zones (2, 10) is aluminum nitride.8. A semiconductor component according to at least one of the precedingclaims, characterized in that the semiconductor material of the driftzones (2, 10) is diamond.
 9. A semiconductor component according to atleast one of the preceding claims, characterized in that a drift zone(2, 10) with identical conductivity type but lower doping is arranged ona highly doped substrate material (1) of silicon carbide.
 10. Asemiconductor component according to at least one of the precedingclaims, characterized in that the substrate material (1) is doped with adoping higher than or equal to 10¹⁸ cm⁻³.
 11. A semiconductor componentaccording to at least one of the preceding claims, characterized in thatthe drift zone region (2) is doped with a doping of 10¹⁴ cm⁻³ to 10¹⁷cm⁻³.
 12. A semiconductor component according to at least one of thepreceding claims, characterized in that the drift zone region (2) has athickness of between 2 μm and 50 μm.
 13. A semiconductor componentaccording to at least one of the preceding claims, characterized in thatthe distance between neighboring pn junctions (9) is between 0.5 μm and20 μm.
 14. A semiconductor component according to at least one of thepreceding claims, characterized in that pn junctions (9) are arranged ingrooves that are etched into the inner drift zone (2).
 15. Asemiconductor component according to at least one of the precedingclaims, characterized in that the Schottky junctions are arrangedadjacent to the pn junctions (9) in the drift zone (2, 10).
 16. Asemiconductor component according to at least one of the precedingclaims, characterized in that doping regions (7, 8), which are insertedinto the drift zone (2, 10), are formed by the semiconductor material ofthe drift zone (2, 10) wish complementary doping.
 17. A semiconductorcomponent according to at least one of the preceding claims,characterized in that the doping regions (7, 8) and the drift zone (2,10) are formed with different semiconductor material.
 18. Asemiconductor component according to at least one of the precedingclaims, characterized in that aluminum and/or boron is inserted into thedrift zone (7, 8) [sic] for the p-doped substrate material (1).
 19. Asemiconductor component according to at least one of the precedingclaims, characterized in that nitrogen and/or phosphor is inserted intothe drift zone (7, 8) [sic] for the n-doped substrate material (1). 20.A semiconductor component according to one of the preceding claims,characterized in that the cathode (K) and the anode (A) are arranged onopposite surfaces of the semiconductor component.
 21. A semiconductorcomponent according to one of the preceding claims, characterized inthat the cathode (K) and the anode (A) are arranged on the same surfaceof the semiconductor component.
 22. A semiconductor component accordingto claim 20, characterized in that the one outer contact (K, A) enclosesthe other outer contact (A, K).
 23. A semiconductor component accordingto at least one of the preceding claims, characterized in that an outercontact (A, K) essentially makes contact with the drift zone (2, 10) atpoints.
 24. A semiconductor component according to at least one of thepreceding claims, characterized in that a highly doped semiconductorregion is located in front of the cathode, which region has the sameconductivity type as the drift zone of the semiconductor (2, 10).
 25. Asemiconductor component according to at least one of the precedingclaims, characterized in that the semiconductor component has acomplementary doping type.
 26. A method for producing a semiconductorcomponent according to one of the claims 1 to 25, characterized in thaton a first doping material with at least 10¹⁸ cm⁻³ doped silicon carbidesubstrate, a silicon carbide layer with a second doping material of thesame charge carrier type in the range of 10¹⁴ and 10¹⁷ cm⁻³ is depositedhomo-epitaxially, whereupon a third doping material with complementarycharge carrier type is inserted structured with the aid of diffusionand/or ion implantation on the surface of the silicon carbide layer thatis arranged far from the substrate in order to form pn junctions, thatsubsequently the component is subjected to a first temperature treatmentbetween 1400° C. and 1700° C., that following the temperature treatment,a first metal coating is deposited on the implanted surface in order toform a Schottky contact and a second metal coating is deposited in orderto form an ohmic contact and that the first and second layers are thenstructured.
 27. A method according to claim 25, characterized in thatthe component is subjected to a final, second temperature treatment. 28.A method according to claim 26 or 27, characterized in that the firsttemperature treatment is carried out such that the component is treatedfor a limited time interval at a temperature of between 500° C. and1500° C. and subsequently is treated further at a temperature of morethan 1500° C.
 29. A method according to at least one of the precedingclaims 26 to 28, characterized in that during the first temperaturetreatment, the component is heated while positioned directly adjacent toelementary silicon.